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jessie_hearn
jessie_hearn
New Participant
August 31, 2017
Answered

Lightroom jpeg export

  • August 31, 2017
  • 4 replies
  • 5197 views

I recently had to reinstall Adobe CC and now when I am exporting the jpegs from Lightroom they are much smaller in size than the full sized RAW Image.  I chose to export at the highest image quality, did NOT select to resize the image to fit, and chose resolution of 300 per inch.  The RAW image is 34 MB and the jpegs are ending up around 5 or 6 MB (they used to be 12-14).  Can anyone help with this? 

Thanks!

    This topic has been closed for replies.
    Correct answer Rob_Cullen

    An excellent link to explain JPG compression and quality- (Note: many of the images are interactive)

    Jeffrey Friedl's Blog » An Analysis of Lightroom JPEG Export Quality Settings

    And "selecting a resolution..."  is pointless for a digital image- Pixel dimensions are the all-important specification.

    (Only Print shops think they need a ppi resolution embedded in a photo file.)

    My analogy to explain 'ppi'  is a football team-  It does not matter if the team is crushed in the changing room or spread out over the field, it is still the same team (the same pixels).  'ppi' only affects the size of a print when you put those same pixels on paper.

    4 replies

    C
    Carmen Ray
    Known Participant
    October 22, 2017

    Hi Jesse, I have just experienced this problem after the update. Have you managed to find a proper answer to your question yet? I am going out of my mind. Please let us know if you have resolved the issue and how. I have spent hours trouble shooting today and no fix yet. Thanks.

    Per Berntsen
    Per Berntsen
    Braniac
    October 22, 2017

    The file size of a jpg depends on three factors:

    • Pixel dimensions
    • Quality setting used when saving/exporting
    • Image content

    Images with large flat areas (like a blue sky) will have a relatively small file size - images with lots of busy sharp detail (or noise) will have a relatively large file size. This is how jpg compression works.

    The difference in file size can be quite dramatic, 5x or more.

    Other than that, you can't really compare the size of a raw file (12 or 14-bit, one channel) with jpg (8-bit, three channels).

    For more information, see File formats and What is a digital image?

      Per Berntsen
      Per Berntsen
      Braniac
      October 23, 2017


      The file size of a jpg is not an indicator of image quality.

      As stated by several people in this thread, the file size of a jpg will vary greatly depending on image content.

      So if you are getting smaller files than you used to (pixel dimensions and quality setting being the same), then you have more flat or smooth areas and/or less sharp detail or noise than in the images than you did previously.

      Did you go to this page File formats  and look at the sample images there?

      So when someone asks for jpgs above or below a certain file size, they don't understand how jpg compression works.

      What they should be asking for is pixel dimensions - which are the only numbers that matter, and that to some degree are an indication of image quality.

      I do my resizing in Photosop

      It's much easier to do the resizing in the Export dialog in Lightroom, then you might not have to use Photoshop at all.

      Of course I can't submit these tiny images.

      Of course you can.

      If you have a used a high quality setting, the images will be fine.

      Also, I don't know how well an 8MB image will print on a large scale, such as a big canvas.

      It's easy to compare the quality of a jpg to the original.

      View both at 1:1 (100%) magnification. If you have exported at 100 quality, you will probably not see any difference at all.

        Rob_Cullen
        Rob_CullenCorrect answer
        Braniac
        August 31, 2017

        An excellent link to explain JPG compression and quality- (Note: many of the images are interactive)

        Jeffrey Friedl's Blog » An Analysis of Lightroom JPEG Export Quality Settings

        And "selecting a resolution..."  is pointless for a digital image- Pixel dimensions are the all-important specification.

        (Only Print shops think they need a ppi resolution embedded in a photo file.)

        My analogy to explain 'ppi'  is a football team-  It does not matter if the team is crushed in the changing room or spread out over the field, it is still the same team (the same pixels).  'ppi' only affects the size of a print when you put those same pixels on paper.

        Regards. My System: Windows-11, Lightroom-Classic 15.0, Photoshop 27.0, ACR 18.0, Lightroom 9.0, Lr-iOS 10.4.0, Bridge 16.0 .
          F. McLion
          F. McLion
          Braniac
          August 31, 2017

          In addition to what Meredith already said: The file size of jpg's is dependent on the contents of an image and can heavily vary also due to the compression algorithms used.

          Of course, a jpg always is much smaller than a RAW which is absolutely normal.

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          meredithb8081254
          meredithb8081254
          Participating Frequently
          August 31, 2017

          Hi Jessie,

          If you are not resizing then you would not be selecting a resolution you would only be selecting to export to jpeg.

          There is a check mark also available that you might have checked that has a file size limit. It might be what is the culprit.

          I am wondering if either you really are resizing on the export by adding in the resolution or if you have a file size limit.

          Meredith

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